An ultrasonic diagnostic apparatus is a medical equipment for obtaining an ultrasound image of a target region in an object so as to provide clinical information of the target region, such as lesion or neoplasm information of internal organs, fetus information and the like. Typically, the ultrasonic diagnostic apparatus comprises at least one probe for radiating an ultrasonic wave to the target region and receiving an echo signal reflected from the target region. The probe has a transducer for converting an ultrasonic signal into an electric signal.
Recently, certain techniques for acquiring a 3-dimensional (3D) ultrasound image by moving the transducer have been developed to obtain more accurate diagnosis.
FIG. 1 is a perspective view schematically showing an inner structure of a prior art ultrasonic probe. FIG. 2 is a perspective view showing a device for guiding the movement of a transducer of a prior art ultrasonic probe.
As shown in the drawings, a prior art ultrasonic probe is equipped with a transducer 10 for converting an ultrasonic signal into an electric signal, a motor 30 for generating driving power for moving the transducer 10, and means for transmitting the power from the motor 30 to the transducer 10. Such components are mounted to a supporting frame 20, which is contained in a housing (not shown).
The supporting frame 20 includes rectangular verges at its upper portion. A pair of guide rails 22 is mounted on the opposing verges of the supporting frame 20 such that the transducer 10 is positioned between the pair of guide rails 22. Slots 24 are formed lengthwise at the side surfaces of the guide rails 22 opposite to both side-ends of the transducer 10. Each slot 24 has a side wall and a bottom wall.
Brackets 12, to which bearings 16 are rotatably mounted, are coupled to both side-ends of the transducer 10. Supporting shafts 14 for supporting the bearings 16 are fixed to the brackets 12. The supporting shafts 14 horizontally extend toward the slots 24 of the guide rails 22 and the bearings 16 are received within the slots 24. The brackets 12 are located apart from the side surfaces of the guide rails 22 by predetermined gaps in order to avoid any undesired friction therebetween. When the driving power of the motor 30 is transmitted to the transducer 10 by the power-transmitting means, the transducer 10 moves along the guide rails 22 while the bearings 16 roll on the bottom walls of the slots 24.
However, during the movement of the transducer, the transducer may rattle between the guide rails due to the operational vibration of the motor or a manufacturing or assembling error. Thus, a friction may occur between the side surfaces of the guide rails and the bearing-supporting brackets. Such a friction causes operational noises or vibrations, and may further cause wears or deformations of the components. Further, the transducer moves somewhat roughly by the friction and the ultrasonic wave is radiated irregularly. As such, the image quality becomes degraded, which can cause an erroneous diagnosis.